文档名：绝缘轴承对变频电机高频轴电流的抑制机理与效果
摘要：随着功率半导体器件的发展,脉宽调制技术被广泛应用于变频电机调速系统,显著提高了电机的动态性能,同时也带来了严重的轴承电蚀问题.绝缘轴承具有安装便捷、可靠性高的优点,是目前轨道交通、风力发电等行业主要采用的电蚀抑制措施.但是绝缘轴承对于变频器引起的高频轴电流的抑制机理、抑制效果及其与绝缘涂层参数之间的关系,有待于进行更深入的理论和实验研究.该文分析了变频电机轴电流的产生机理,建立了考虑绝缘涂层参数的变频电机轴电流等效电路模型;分析了全膜润滑稳态过程和放电击穿瞬态过程中,绝缘轴承对于轴电压和轴电流的抑制效果,以及涂层厚度、介电常数对抑制效果的影响.搭建了变频电机轴电流测试平台,进行了绝缘轴承和普通轴承的对比实验.仿真和测试结果表明,采用绝缘轴承可以降低润滑油膜上所承载的一部分电压,可以大大减小轴电流的击穿次数及幅值.
Abstract：Duetoconvenientinstallationandhighreliability,insulatedbearingsarethemainelectriccorrosionsuppressionmeasureusedinrailtransit,electricvehicles,andmanyotherindustries.However,high-frequencybearingcurrentscausedbyfrequencyconvertersposechallengesduetothecapacitoreffectofinsulationcoatings,whichconstitutesthecouplingpathofthebearingcurrent,resultinginbearingelectricalcorrosionfailures.Therefore,abearingcurrentequivalentcircuitmodelofmotor-bearingcouplingisestablished.Theinhibitionmechanism,effect,andinfluencingfactorsofinsulatedbearingsonhigh-frequencybearingcurrentareanalyzed,providingatheoreticalbasisforthedesignofinsulatingbearingcoatingparameters.Firstly,themechanismofthehigh-frequencybearingcurrentinvariable-frequencymotorsisanalyzed,andacouplingmodelbetweenthemotorandbearingisestablished.Thebearingmodelconsidersthedynamicparametersofoilfilms,theequivalentimpedanceofinsulationcoatings,andthetransientprocessofdischargebreakdown.Secondly,takinga190kWinductionmotorasanexample,straymotorcapacitanceandequivalentinsulationcoatingcapacitanceareextractedbyimpedancetestcurves.Then,basedontheequivalentcircuitmodel,thesuppressioneffectofinsulatingcoatingsonbearingvoltageandbearingcurrentunderfullfilmlubricationanddischargebreakdownprocessisanalyzed.Theinfluenceofinsulatingcoatingthicknessanddielectricconstantontheinhibitioneffectisstudiedbysimulation.Finally,abearingcurrenttestplatformforvariablefrequencymotorsisbuilt.Variablefrequencypowersupplyandexternalbearingvoltagetestsaredesignedtoverifythemodelandanalyzetheactualsuppressioneffect.Accordingtothesimulationresults,thebearingvoltageandbearingcurrentcanbereducedbydecreasingthedielectricconstantorincreasingthethicknessoftheinsulatingcoating.However,infullfilmlubrication,insulatedbearingscannotreducethebearingpartialvoltageratio(BVR)bymorethan10%.Theinhibitioneffectonbearingcurrentisaffectedbythebreakdownresistanceofthebearing.Whenthebreakdownresistanceisabove100Ω,thereductioninbearingcurrentisnotmorethan20%.ThetestresultsshowthatBVRis5.35%～5.97%usingordinarybearings,andBVRisois5.04%～5.51%usinginsulatedbearings.Thepeakvalueofbearingcurrentisdistributedbetween40～100mAwithordinarybearings.Thebearingcurrentisallsuppressedbelow70mAusinginsulatedbearings,significantlyloweringdischargeactivitycomparedtoordinarybearings.Thefollowingconclusionscanbedrawnfromsimulationandtestresults:(1)Whenthelubricatingoilfilmofthebearingisnotbrokendown,thecapacitanceoftheinsulatingbearingcoatingcansharepartofthebearingvoltage,thusreducingtheprobabilityofthebreakdownoftheoilfilm.However,theinhibitioneffectislimitedinfullfilmlubrication.(2)Insulatingcoatingthicknessanddielectricconstantinfluencetheinhibitioneffectofinsulatedbearingsonbearingvoltage,andtheirdesignshouldconsiderthebreakdownthresholdofbearingvoltage.(3)Increasingthecapacitanceoftheinsulationcoatingreducesbearingcurrentafteroilfilmbreakdownanddischargeactivity.(4)Thesuppressioneffectofinsulatedbearingsonbearingcurrentisaffectedbythebreakdownresistance.Ifthebreakdownresistanceistestedindifferentworkingconditionsinadvance,coatingparameterscanbedesignedaccordingtothecorrespondingsuppressiontarget.
作者：李知浩 刘瑞芳 张亮亮 李伟力 赵秦聪 Author：LiZhihao LiuRuifang ZhangLiangliang LiWeili ZhaoQincong
作者单位：北京交通大学电气工程学院北京100044精进电动科技股份有限公司北京100015
刊名：电工技术学报
Journal：TransactionsofChinaElectrotechnicalSociety
年，卷(期)：2024, 39(4)
分类号：TM34
关键词：变频驱动 轴电压 轴电流 绝缘轴承
Keywords：VariablefrequencyACmotor bearingvoltage bearingcurrent insulatedbearing
机标分类号：TM307TN303TG174
在线出版日期：2024年3月5日
基金项目：中央高校基本科研业务费专项项目，北京市自然科学基金，高功率高效电驱动总成系统开发，产业化项目绝缘轴承对变频电机高频轴电流的抑制机理与效果[
期刊论文] 电工技术学报--2024, 39(4)李知浩 刘瑞芳 张亮亮 李伟力 赵秦聪随着功率半导体器件的发展,脉宽调制技术被广泛应用于变频电机调速系统,显著提高了电机的动态性能,同时也带来了严重的轴承电蚀问题.绝缘轴承具有安装便捷、可靠性高的优点,是目前轨道交通、风力发电等行业主要采用的电蚀...参考文献和引证文献
参考文献
引证文献
本文读者也读过
相似文献
相关博文
绝缘轴承对变频电机高频轴电流的抑制机理与效果 The Suppression Mechanism and Effects of Insulated Bearings on High Frequency Bearing Current
绝缘轴承对变频电机高频轴电流的抑制机理与效果.pdf
- 文件大小:
- 1.51 MB
- 下载次数:
- 60
-
高速下载
|
